Search found 245 matches

by Luciano Garelli
Thu Jun 09, 2016 8:44 pm
Forum: code_saturne usage
Topic: mass flow over an internal surface
Replies: 11
Views: 6722

Re: mass flow over an internal surface

Hello, Generally the mass flow rate is computed as \dot{m}=\rho \cdot \vec{V} \cdot \vec{n} \cdot A . In the documentation is mention that the surface vector of the faces are oriented outwards. Also, I think that a simple example like a fluid flow in a tube with an inlet and outlet can answer this q...
by Luciano Garelli
Thu Jun 09, 2016 2:20 pm
Forum: code_saturne usage
Topic: Expression check failed unexpectedly
Replies: 6
Views: 4261

Re: Expression check failed unexpectedly

Hello, I'm not a Mac user...but I have searched about this problem and several Mac users report this PyQt/Qt problem using dialog box in different softwares. My first recommendation is try to install CS 4.0 and check if works. May be the developers can give you same additional information about this...
by Luciano Garelli
Thu Jun 09, 2016 1:17 pm
Forum: code_saturne usage
Topic: Expression check failed unexpectedly
Replies: 6
Views: 4261

Re: Expression check failed unexpectedly

Hello,

I think that this error come from Qt when managed the dialog box. Is this error only produced with the velocity initialization box?

Could you give more information about what OS are you using? Did you try to compile another version of CS (e.g. 4.0).

Regards,

Luciano
by Luciano Garelli
Tue May 31, 2016 7:16 pm
Forum: code_saturne usage
Topic: Jacobi: error (divergence) solving for Velocity
Replies: 17
Views: 7550

Re: Jacobi: error (divergence) solving for Velocity

Hello,

I attach the case, the listing and the source files. I noted that you changed the Cdest and Cprod parameters. I hope that you find it useful and can solve this problem

Regards,

Luciano
by Luciano Garelli
Mon May 30, 2016 5:14 pm
Forum: code_saturne usage
Topic: Velocity Initialization
Replies: 1
Views: 1809

Re: Velocity Initialization

Hello, 1) You can define multiple zones to be initialized with different values (e.g. Different velocities). This is can be done in the GUI under the Volume Condition Tab -> Definition of volume regions. Here you can add multiple zones and specify a selection criterion for the cells (e.g. coordinate...
by Luciano Garelli
Mon May 30, 2016 2:47 pm
Forum: code_saturne usage
Topic: Jacobi: error (divergence) solving for Velocity
Replies: 17
Views: 7550

Re: Jacobi: error (divergence) solving for Velocity

Hello, The cavitation number and vapor pressure are absolute pressures. So, if you want to use a P_{ref}=P_0>0 , the outlet gauge pressure P_g for a given cavitation number is given by, P_{abs}=0.5 \rho V^2+P_{v}=P_g+P_{ref} , wherewith P_g=0.5 \rho V^2+P_{v}-P_{ref} . In the figure that you attach ...
by Luciano Garelli
Fri May 27, 2016 8:37 pm
Forum: code_saturne usage
Topic: Jacobi: error (divergence) solving for Velocity
Replies: 17
Views: 7550

Re: Jacobi: error (divergence) solving for Velocity

Hello, As Benoît mention the problem was in the pressure. In your case if you set a P_{ref}=0 and the outlet pressure according to the cavitation number \sigma you will get the cavitation of the fluid at the throat. I have run you case with a dt=5e-6 [s] and the results are reasonable according to t...
by Luciano Garelli
Thu May 26, 2016 3:50 pm
Forum: code_saturne usage
Topic: Velocity profile from file
Replies: 6
Views: 3739

Re: Velocity profile from file

Hello, Inside of the boundary faces loop, you can access to the coordinates of the centers of the boundary faces thought the pointer cdgfbo ! Boundary faces of group '3' call getfbr('3', nlelt, lstelt) do ilelt = 1, nlelt ifac = lstelt(ilelt) ! y-coordinate Face center ycoord = cdgfbo(2, ifac) enddo...
by Luciano Garelli
Tue May 24, 2016 9:02 pm
Forum: code_saturne usage
Topic: Jacobi: error (divergence) solving for Velocity
Replies: 17
Views: 7550

Re: Jacobi: error (divergence) solving for Velocity

Hello Amir, I was looking the cavitation.f90 file and the theory documentation, because I never work with cavitation. In the theory documentation of the CS 4.0.0 the vaporization source terms are m^+ = -\dfrac{C_{prod} \rho_l \min \left( p-p_V,0 \right)}{0.5\rho_lu_\infty^2t_\infty}, m^- = -\dfrac{C...
by Luciano Garelli
Fri May 20, 2016 2:16 pm
Forum: code_saturne usage
Topic: Jacobi: error (divergence) solving for Velocity
Replies: 17
Views: 7550

Re: Jacobi: error (divergence) solving for Velocity

Hello amir,

Could you also post the case and the mesh files?

Regards,

Luciano